Documenta Ophthalmologica最新文献

Purpose: It is established that the mfERG is altered in type 2 diabetes (T2DM). The P1 implicit time (IT) becomes delayed even before retinopathy is present. This has been associated with the duration of damage to retinal cells from hyperglycemia. However, patients withT2DM and prediabetes also have changes in insulin values. The impact of elevated or reduced blood insulin on retinal function using mfERG has not been explored. Here we evaluate the the relationship between blood insulin levels and mfERG parameters in patients with and without T2DM and prediabetes.

Methods: 66 subjects (age 50.4 ± 10.5) were included in this cross-sectional study. Subjects were asked if fasted upon presentation. HbA1c was taken and used to categorize subjects into groups as controls (< 5.7%), prediabetes (5.7-6.4%) or T2DM (> 6.4% or previously diagnosed). Insulin was collected from finger stick and was analyzed via ELISA. A mfERG (103 hexagons) was performed (VERIS 6.3) with 4-min m-sequence at near 100% contrast. Data was evaluated for ring hexagons, as well as averaged together for P1 IT. No subjects had retinopathy or were taking exogenous insulin. Data were evaluated through ANOVA for comparisons of groups and as well as with multivariate regression analysis.

Results: There was a strong positive correlation between fasting blood glucose and mfERG IT (P < 0.002) in all subjects. There was also a negative relationship between averaged mfERG IT and fasted blood insulin concentration (P = 0.035) after age, T2DM duration and blood glucose were controlled for in a multivariate regression. There was a significant difference in mfERG IT between the groups (p = 0.008) with T2DM exhibiting the longest IT, but no difference between controls and prediabetes. There was no difference in insulin levels between groups, nor were there any significant relationships between insulin and mfERG IT for those who were not fasted.

Conclusions: Reduced blood insulin is associated with IT delays under overnight fasted conditions, which suggests a lack of insulin may impair retinal function. Future work should examine these associations of retinal function with insulin under well controlled and standardized postprandial conditions such as during oral glucose tolerance testing.

Importance: Central retinal artery occlusion (CRAO) is typically associated with older patients with cardiovascular risk factors. However, its occurrence in younger patients without these risk factors suggests the need to explore rare genetic conditions. Identifying genetic disorders like adenosine deaminase 2 deficiency (DADA2), a vasculitic disease, can be critical in such cases to prevent further complications.

Objective: To report the challenging diagnosis of two cases of CRAO in brothers under the age of 40, leading to the diagnosis of DADA2, a rare genetic vasculitic disorder.

Results: A 34-year-old man and his 32-year-old brother, both without significant medical histories, presented with CRAO eight years apart. Extensive diagnostic evaluations, including blood tests, imaging, and autoimmunity panels, failed to identify common causes. Progressive neurological symptoms in the older brother and the similar presentation in his sibling led to further investigation, including genetic testing. A homozygous mutation c.752C > T p.(Pro251Leu) in the CECR1 gene confirmed the diagnosis of DADA2 in both brothers.

Conclusion: These cases underscore the importance of considering genetic disorders like DADA2 in young patients presenting with unexplained vascular occlusions. DADA2, characterized by vasculitis, immune dysregulation, and hematologic disorders, can manifest variably, complicating early diagnosis. Effective treatment with TNF inhibitors can prevent further vision loss and mitigate systemic complications. To our knowledge, these are the first reported cases of DADA2 with CRAO as the initial manifestation without prior clinical findings.

Purpose: To compare signal-to-noise levels in ERG recordings obtained with contact lens electrodes and adhesive skin electrodes.

Methods: 23 subjects were studied. Full-field ERGs were recorded according to ISCEV standards simultaneously with ERG-jet corneal contact lens electrodes and LKC Technologies Sensor Strip adhesive skin electrodes. B-wave amplitude or peak-to-peak amplitude was used as a measure of signal strength. Noise was estimated using the " ± averaging method." Comparisons between signal strength, absolute noise levels, and signal-to-noise ratios between contact lens and skin electrodes were performed by linear regression.

Results: Comparisons of signal strength for LA 3, 30-Hz, DA 0.01, and DA 3 responses, yielded regression coefficient ß values of 0.37, 0.39, 0.39, and 0.35, respectively. For the entire data set, the regression coefficient ß value was 0.36 (95% confidence limits 0.34 - 0.38). The grand average ERG noise for all ERG stimuli was 13.8 µV for contact lens electrodes and 13.0 µV for skin electrodes (not significant: p = 0.66 for paired t-test). For signal-to-noise ratios, regression ß coefficients for contact lens and adhesive skin electrodes for LA 3, 30-Hz, DA 0.01, and DA 3 stimuli were 0.25, 0.39, 0.50, and 0.36 respectively. The ß coefficient for the amalgamated data set was 0.33 (95% confidence limits 0.30- 0.36).

Conclusions: Overall ERG amplitudes obtained with skin electrodes were 1/3 those obtained with contact lens electrodes. Absolute noise levels were similar. Signal-to-noise levels with skin electrodes were 1/3 those seen with contact lens electrodes. Implications for signal-averaging in clinical applications are discussed.

Purpose: Multiple mitochondrial syndromes, such as Kearns-Sayre, involve the concurrence of diabetes mellitus and inherited pigmentary retinopathy. It is rare, however, for proliferative disease to develop in these patients as existing inner retinal dysfunction is thought to be protective.

Methods: To our knowledge this is the first description of proliferative diabetic retinopathy (PDR) in Kearns-Sayre syndrome.

Conclusion: A number of additional considerations need to be recognised when treating PDR in Kearns-Sayre syndrome. Given the risk of further visual field losses with panretinal photocoagulation, there should be a preference for primary anti-VEGF therapy in a compliant patient. PDR in inherited retinal disease appears to be very anti-VEGF responsive and may not require the standard monthly frequency of treatment, even from initiation.

Purpose: To explore changes in the electroretinogram (ERG) following methylphenidate use in attention-deficit/hyperactivity disorder (ADHD).

Methods: Light adapted ERGs were recorded in five individuals (3 male and 2 female, age range 13.6-21.8 years) with a diagnosis of ADHD. Six flash strengths ranging from 71 to 446 Td.s were qualitatively evaluated following a minimum of 24 h without any medication and from 2 to 6 h following the individuals' standard slow-release (XL) methylphenidate dose that ranged from 18 to 60 mg.

Results: Of the six flash strengths, the 178 Td.s strength revealed changes in four of the five participants with a median 27.4% increase in b-wave amplitude. For three individuals there was an increase in the a-wave amplitude and for two of the same individuals there was also a noticeable pronouncement of the oscillatory potentials. The a-wave amplitude showed a greatest median increase at the 446 Td.s flash strength of 25.8%. One individual - on the highest dose (60 mg) exhibited no morphologically distinct changes in the ERG. No differences in the time to peaks of the a- and b-wave were observed for any individual.

Conclusion: The a- and b-wave amplitudes of the light adapted ERG could provide insights into the effect of methylphenidate in ADHD.

Purpose: The aim of this study was to compare retinal and optic disc functions as well as vascular structures in dominant eyes (DE) and non-dominant eyes (NDE) among healthy adults using pattern electroretinogram (PERG), optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) tests.

Methods: Seventy-two eyes of 36 healthy subjects with bilateral visual acuity of 1.0 were included. Parameters such as intraocular pressure (IOP), cycloplegic spherical equivalent value (SE), PERG, retinal nerve fiber layer (RNFL) thicknesses and OCTA measurements were evaluated. Ocular dominance was determined using the hole-in-the-card test.

Results: Of the participants, 67% were female, with a median age of 28 (min-max.18-35) years. Right eye dominance was observed in 61.2% of cases, while left eye dominance was seen in 38.8%. There was no significant difference in refractive values between eyes with right and left eye dominance (0.60 ± 0.40 and 0.41 ± 0.28, p = 0.42). The dominant eyes showed significantly higher P50 amplitude (10.2 µV vs. 9.2 µV, p = 0.003) and shorter peak time (47.9 ms. vs. 48.6 ms, p = 0.01) when compared to the nondominant eyes. There were comparable values in the peak times and amplitudes of the N95 component between the dominant and nondominant eyes. The RNFL layer was thicker on average (p, 0.001) as well as in the nasal and inferior quadrants of the dominant eyes (p < 0.05). OCTA analysis revealed no significant differences in the peripapillary and macular capillary vascular densities between dominant and nondominant eyes (p > 0.05), except for the deep whole capillary density in the macula, which was significantly higher in the dominant eyes (p = 0.02).

Conclusion: Our results indicate the existence of functional and structural relationships related to ocular dominance. Future studies provide further insights into ocular dominance and its relationship with eye structure.

Purpose: To report a novel hemizygous nonsense variant in the CACNA1F gene associated with congenital stationary night blindness (CSNB) in a pediatric patient, emphasizing the utility of portable electroretinography (ERG) and genetic testing in diagnosing unexplained visual impairments.

Methods: The patient, a 5-year-old male, underwent comprehensive clinical evaluation, including detailed anterior segment and fundus examinations, full-field electroretinogram (ffERG) using a RETeval™ portable device, and whole exome sequencing (WES) to elucidate the genetic basis of his visual impairment. Structural modeling of the mutated protein was performed using SWISS-MODEL and PYMOL.

Results: Best-corrected visual acuity was 0.4 logMAR bilaterally, with unremarkable anterior segment and fundus examinations. FFERG revealed significant abnormalities consistent with incomplete CSNB: severely reduced rod response in dark-adapted (DA) 0.01, negative waveform with b/a wave ratio < 1.0 in DA 3.0, and diminished cone response in light-adapted ERG. WES identified a novel pathogenic variant in the CACNA1F gene (c.1234G > T, p.E412*), inherited maternally. This variant introduces a premature stop codon at position 412, likely resulting in a truncated CACNA1F protein.

Conclusions: This case highlights the importance of comprehensive clinical assessments and genetic testing in pediatric patients with unexplained visual impairments, revealing a novel CACNA1F variant that expands our understanding of CSNB. The use of a portable ERG device proved particularly valuable in assessing retinal function in this young patient. Further investigations are warranted to elucidate the clinical implications of this novel pathogenic variant.

Purpose: Several studies have reported that glaucoma patients have abnormal photopic negative response (PhNR) results compared to reference control subjects. The International Society for Clinical Electrophysiology of Vision (ISCEV) released an extended protocol for PhNR (I-PhNR) in 2018. The purpose of this study was to compare the I-PhNR protocol to a similar protocol modified (M-PhNR) to enhance the performance of the method in detecting glaucomatous damage.

Methods: Thirty subjects were enrolled in this study (12 glaucoma patients, 10 glaucoma suspects, 8 normal controls). PhNR tests were conducted with a Diagnosys E3 mobile system (Diagnosys LLC, Lowell, MA). I-PhNR tests utilized all parameters specified by the ISCEV requirement. M-PhNR tests used the same parameters as the ISCEV tests with the exceptions of a 5-45 Hz bandpass filter and a novel, objective sweep-selection parameter. According to the ISCEV protocol, the PhNR relative to baseline (i.e., BT), a-wave and b-wave response amplitudes and BT/b-wave amplitude ratios were measured. Coefficients of variation, receiver operating characteristic (ROC) curves, and t-tests were used to assess the data from one randomly chosen eye per subject.

Results: The M-PhNR protocol resulted in a decrease in the intra-subject repeat test coefficient of variation and a decrease in the average inter-subject coefficient of variation for the glaucoma subjects. The ROC curves demonstrated an increase in the area under the curve (AUC) for the M-PhNR compared to the I-PhNR protocol. The sensitivity and specificity were also greater for the M-PhNR protocol.

Conclusions: The M-PhNR protocol resulted in a decrease in intra-subject and inter-subject data variability which resulted in a significant increase in the ROC AUC, sensitivity, and specificity for glaucoma. Thus, the M-PhNR protocol shows promise as a better diagnostic tool than the I-PhNR protocol for detecting glaucoma.